地面抽采钻井剪切变形破坏的关键层影响效应

Key rock strata effecting analysis on surface borehole shear deformation fracture

地面钻井抽采煤层瓦斯不影响工作面回采且可以采前预抽、采动抽采和采空区抽采,是一种解决矿井高瓦斯行之有效的方式。但受煤层回采的影响,当回采工作面推过地面钻井位置后钻井套管迅速发生破坏,无法充分发挥其抽采采空区瓦斯的效应。因此,建立了基于采区上覆岩层层面剪切滑移效应的地面钻井剪切变形破坏模型,并对关键层对钻井套管剪切变形的影响效应进行了研究,以为地面抽采钻井防护提供工程指导,同时,运用3DEC离散元数值模拟程序对模型进行了模拟分析,并与现场工程实例进行对比验证。结果证明,模型描述的规律性是可靠的,具有较强的工程指导意义。

A good method for creating a surface borehole for withdrawing coal strata methane is to build before excavation and use during the whole process. But the excavation greatly affects the overlying rock strata, and when the excavation face passes through the surface borehole place, the surface borehole quickly fractures. A shear deformation fracture model based on the rock strata shear slippage effect is set up, and the key rock strata effect is researched. At the same time, a 3DEC simulation model and an engineering example are generated to validate the theoretical model. The result shows that the model is reliable and has good engineering application value.